Relationship between UGT1A1*27 and UGT1A1*7 polymorphisms and irinotecan-related toxicities in patients with lung cancer

The Correlation Between UGT1A1 Gene Phenotypes and the Clinical Prognosis of Advanced Colorectal Cancer After FOLFIRI Therapy

Objective: This study aimed to investigate the correlations between the different phenotypes of the uridine diphosphate glucuronyl transferase (UGT) 1A1 gene and the treatment of advanced colorectal cancer with the FOLFIRI regimen. Materials and Methods: A total of 240 advanced colorectal cancer patients with stage IV colon cancer or recurrence after radical surgery between January 2014 and December 2018 were included in a retrospective study. All participants were treated with the FOLFIRI regimen until the disease progressed or an intolerable level of toxicity occurred. Results: In this study, three phenotypes of the UGT1A1 gene promoter were found: the homozygous wild type (TA6/6 type, 78.3%), the heterozygous mutant type (TA6/7 type, 19.6%), and the homozygous mutant type (TA7/7 type, 2.1%). Compared with TA6/7 and TA6/6, the risk of nonresponse to FOLFIRI chemotherapy increased by 16%, but the difference was not significant. The risk of death increased by 24%, and there was no significant difference. There was a risk of hematologic and nonhematologic adverse reactions occurring in TA6/7 and TA6/6, and the total risk of adverse reactions increased by 9.3773 times among patients with more than two metastatic organs. Compared with patients with TA6/6, the risk of toxic side-effects increased by 42.8066 times (p = 0.0259) for patients with TA6/7. Among patients who received FOLFIRI chemotherapy for more than four cycles, the proportion with TA6/7 was greater than that with TA6/6. Compared with those with TA6/6, patients with TA6/7 showed a higher risk of hematologic toxicity (22.3246 times, p = 0.0035). Conclusion: The TA6/7 in patients with advanced colorectal cancer had more than two metastatic organs, and received FOLFIRI chemotherapy for more than four cycles compared with TA6/6 patients. Furthermore, the risk of hematologic and nonhematologic adverse reactions significantly increased, and the risk of digestive-tract and hematologic toxicity was more significant.

Human variability in isoform-specific UDP-glucuronosyltransferases: markers of acute and chronic exposure, polymorphisms and uncertainty factors

UDP-glucuronosyltransferases (UGTs) are involved in phase II conjugation reactions of xenobiotics and differences in their isoform activities result in interindividual kinetic differences of UGT probe substrates. Here, extensive literature searches were performed to identify probe substrates (14) for various UGT isoforms (UGT1A1, UGT1A3, UGT1A4, UGT1A6, UGT1A9, UGT2B7 and UGT2B15) and frequencies of human polymorphisms. Chemical-specific pharmacokinetic data were collected in a database to quantify interindividual differences in markers of acute (Cmax) and chronic (area under the curve, clearance) exposure. Using this database, UGT-related uncertainty factors were derived and compared to the default factor (i.e. 3.16) allowing for interindividual differences in kinetics. Overall, results show that pharmacokinetic data are predominantly available for Caucasian populations and scarce for other populations of different geographical ancestry. Furthermore, the relationships between UGT polymorphisms and pharmacokinetic parameters are rarely addressed in the included studies. The data show that UGT-related uncertainty factors were mostly below the default toxicokinetic uncertainty factor of 3.16, with the exception of five probe substrates (1-OH-midazolam, ezetimibe, raltegravir, SN38 and trifluoperazine), with three of these substrates being metabolised by the polymorphic isoform 1A1. Data gaps and future work to integrate UGT-related variability distributions with in vitro data to develop quantitative in vitro-in vivo extrapolations in chemical risk assessment are discussed.

Carbon monoxide breath test assessment of mild hemolysis in Gilbert's syndrome

BACKGROUND

Mild hemolysis is difficult to determinate by traditional methods, and its role in Gilbert's syndrome (GS) is unclear. The main aims were to inspect the erythrocyte (RBC) survival in GS by using Levitt's carbon monoxide (CO) breath test and to assess its contribution to unconjugated hyperbilirubinemia.

METHODS

Fifty subjects with GS and 1 with type-II Crigler-Najjar syndrome (CN2) received RBC lifespan measurement with Levitt's CO breath test. Mean RBC lifespan was compared with normal referral value. Correlations of serum total bilirubin (TB) with RBC lifespan, blood panel data, demographic factors, and uridine diphosphate glucuronosyltransferase (UGT1A1) mutation load were calculated by Spearman analysis. Susceptibility factors for mild hemolysis were analyzed by multivariate regression analysis.

RESULTS

The mean RBC lifespan of the GS subjects was significantly shorter than the normal reference value (95.4 ± 28.9 days vs 126 days; t = -7.504, P < .01), with 30.0% below the lower limit of the normal reference range (75 days). The RBC lifespan of the participant with CN2 was 82 days. Serum TB correlated positively with UGT1A1 mutation load (γ = 0.281, P = .048), hemoglobin (γ = .359, P = .010) and hematocrit (γ = 0.365, P = .010), but negatively with RBC lifespan (γ = -0.336, P = .017). No significant susceptibility factors for mild hemolysis were found.

CONCLUSIONS

The results indicate that mild hemolysis indeed, exists in a portion of patients with GS and might serve as an important contributor to unconjugated hyperbilirubinemia in addition to UGT1A1 polymorphism. Further studies on the mechanism and the potential risks in various medical treatments might be wanted.

A phase II trial of irinotecan in patients with advanced or recurrent endometrial cancer and correlation with biomarker analysis

OBJECTIVE

Chemotherapy for advanced or recurrent endometrial cancer requires further development. Irinotecan hydrochloride (CPT-11) suppresses tumor growth in several endometrial cancer strains. The present study evaluated the anti-tumor activity and toxicity of CPT-11 in patients with advanced or recurrent endometrial cancer.

METHODS

Enrolled patients had advanced endometrial cancer with measurable lesions and received 2 pretreatment regimens. A 90-minute intravenous infusion of CPT-11 (100 mg/m²) was given on days 1, 8, and 15 of a 4-week cycle, aiming for an effect with ≤2 cycles. Treatment was continued until the primary disease worsened or severe toxicity occurred. The primary endpoint was response rate, and the secondary endpoints were progression-free survival, overall survival, and adverse events. Antitumor effect and adverse events were evaluated according to RECIST version 1.1 and NCI-CTC AE version 3.0, respectively.

RESULTS

Twenty-two patients were registered (11 endometrioid carcinomas and 11 serous carcinomas). The median duration of the treatment-free interval (TFI) was 7.5 months, and the median number of administered cycles per patient was 4. Response rate was 36.4% (complete response: 1 patient, partial response: 7 patients). Clinical benefit rate, including stable disease, was 77.3%. Median progression-free and overall survival was 4.4 and 18.4 months, respectively. Observed adverse events included grade 4 hematotoxicity (neutropenia and thrombocytopenia), and grade 2 or 3 non-hematotoxicity (diarrhea). All adverse events were manageable. Biomarker predictors of therapeutic effectiveness were not observed.

CONCLUSION

As a single agent, CPT-11 has anti-tumor activity for advanced or recurrent endometrial cancer and has manageable adverse events.

Comparison of tumor related signaling pathways with known compounds to determine potential agents for lung adenocarcinoma

Background

This study compared tumor‐related signaling pathways with known compounds to determine potential agents for lung adenocarcinoma (LUAD) treatment.

Methods

Kyoto Encyclopedia of Genes and Genomes signaling pathway analyses were performed based on LUAD differentially expressed genes from The Cancer Genome Atlas (TCGA) project and genotype‐tissue expression controls. These results were compared to various known compounds using the Connectivity Mapping dataset. The clinical significance of the hub genes identified by overlapping pathway enrichment analysis was further investigated using data mining from multiple sources. A drug‐pathway network for LUAD was constructed, and molecular docking was carried out.

Results

After the integration of 57 LUAD‐related pathways and 35 pathways affected by small molecules, five overlapping pathways were revealed. Among these five pathways, the p53 signaling pathway was the most significant, with CCNB1, CCNB2, CDK1, CDKN2A, and CHEK1 being identified as hub genes. The p53 signaling pathway is implicated as a risk factor for LUAD tumorigenesis and survival. A total of 88 molecules significantly inhibiting the five LUAD‐related oncogenic pathways were involved in the LUAD drug‐pathway network. Daunorubicin, mycophenolic acid, and pyrvinium could potentially target the hub gene CHEK1 directly.

Conclusion

Our study highlights the critical pathways that should be targeted in the search for potential LUAD treatments, most importantly, the p53 signaling pathway. Some compounds, such as ciclopirox and AG‐028671, may have potential roles for LUAD treatment but require further experimental verification.